Shaft seal



Jan. 25, 1944.

T. J, HSHELLENBERGE SHAFT SEAL Filed Aug. 15, 1940 2 Sheets-Shea?l l I ll y Suvcntor "r. J. si-uaLLENBERGERv Cttorncg Jan. 25, 1944. T. J. sHELLENBERGr-:R 2,340,022.

SHAFT SEAL Filed Aug. 15, 1940. 2 sheets-sheet` 2 Fin?. 2

AIR UNDER lnaasuma- 44 24 Srwentor r. J. SHELLENBERQE'R Gttorueg Patented `Ian. 25, 1944 NT OFFICE sHAF'r SEAL Titus James Shellenberger, York, Pa., assigner to Read Machinery C0., Inc., York, Pa., a corporation of Pennsylvania Application August 15, 1940, Serial No. 352,740

This invention relates to dough mixers and the like, and more particularly to means for sealing the agitato;1 shafts thereof at the joints between the shafts and the journals therefor. Dough mixing machines have a bowl which may be provided with a trunnion at each end by which the bowl is rotatably mounted so that when the dough is mixed the bowl can be turned or tilted from its mixing position to a discharge position. Y

Rotatable within the,` bowl is an agitator which is mounted on a shaft that extends through the trunnions of the bowl. The agitator shaft is adapted to be operated at high speed by mechanism independent of the bowl tilting or rotating' mechanism.

lThe batches of ingredients which are placed in the bowl for mixing consist of dry materials,

means by which shaft and the trunnions of the bowl cfa mixing machine are sealed.

Another object of the invention is to provide for the agitator shaft of a which is simple in construction, and reliable and exact in function under all conditions of service.

Another object of the invention is to provide an. improved means for sealing the joints between the agitator shaft and the uid within therbowl is prevented. by the high air pressure from lflowing outwardly through the joints.

The invention useful of which it is composed, more fully described and claimed.

In the accompanying drawings:

Fig. 1 is an elevation, partly in section, of a dough mixing machine constr cted according to the present invention; and

Fig. 2 is an enlarged section of a portion of the dough mixing machine in which the trunnion 2 Claims. (Cl. 308`36.3)

of the bowl is mounted, showing the sealing means for the agitator shaft.

Referring to the drawings, the dough mixing machine may comprise a casing consisting of a base II, hollow upright ends I 2 and I3, and a top I4 which extends between the upper portions of the ends I2 and I3.

Within the space between the base, the ends, and the top, there is a bowl I5 of The bowl I5 is rotatably supported within the casing for tilting movement through a limited angle of approximately 90, so that after a batch of dough has been mixed the bowl can be turned to discharge position in a well known manner.

For the purpose of rotatably mounting the bowl I5 in the casing, each end wall I6 of the bowl is formed with a boss I1 having an opening I8 therein.

The opening I8 has a diameter considerably larger than the diameter of the agitator shaft I9.

A cylindrical member 20 having an inner centering hub portion 2| mounted in I8, is secured to the boss means of a plate 27 secured to the the hub 2l by screws 28, The plate 2l has a central opening tted with a little clearance on the shaft I9.

The outer end of the chamber 25 Vis closed by means of a ring packing 29 mounted in an annular plate' S0 secured to the hub 2! by cap 2. cap screws 36. The plate 35 is further retained in position by means of a washer 31 secured to the end of the shaft I9 by a set screw 38.

The cover plate 35 is constructed to provide a chamber 3S for the lubricating oil for the bearing 32, and in order to prevent leakage of the oil inwardly of the shaft I9, a ring packing 4B is mounted in an annular grove 4l formed in the plate 33 and disposed around the shaft I9 inwardly with respect to the bearing 32. The packing 45 is similar to the packing 29 heretofore referred to.

In order to introduce air under pressure into chamber 26, the plate 3l) is formed with a threaded opening 42 into which is fitted one end of a pipe 43. The pipe 43 is adapted to be connected to a source shown) by means of a flexible hose 44 connected to the opposite end of said pipe. i

Mounted on the shaft I9 and disposed within the bowl I5 is an agitator 45 of'well known type. The agitator comprises a series of elongated rollers 4B carried by arms 41 at each end of the bowl, said rollers being arranged in parallel relationship to the shaft I9, and being adapted to pick up and knead the dough after the ingredients have been thoroughly mixed. l A

Heretofore, in dough mixing machines of the type shown in Fig. l, it was the practice to install a packing or stuffing box around the shaft I9 where said shaft passes through the end walls of the bowl. Since the ingredients of `the batches of materials being mixed in the bowl consisted of considerable liquid which was thrown violently around the bowl during the initiation of the mixing operation, it was dimcult to provide'a tight seal by the use of the known types `of stuiiing boxes or shaft packings, and consequently when the liquid leaked past the packing glands, due to the presence of flour and other materials therein, the packing glands would become gummed and otherwise damaged or rendered unfit, and, therefore, it was necessary to frequently renew or repair the packing material, Also, during the operation of the mixing machine particles of the packing material would work along the shaft, enter the bowl and become mixed with the dough, thereby rendering the dough unfit for use. Thus, by eliminating the packing material of the usual packing gland and substituting therefor the sealing means of the present invention, no foreign matter can enter the bowl as heretofore. Because of the pressure constantly maintained in chamber 28 by air delivered through pipe 43 in an amount greater than the pressure within the bowl I5, the liquidfwithin cylindrical member Having thus described my invention, what I claim is:

1. A device of the class described, comprising a movable member having an end wall with an opening formed therein, a stationary member arranged in spaced relation to the wall of said movable member and having an opening formed therein in alinement with the opening in the end wall of said movable member, the diameter of the opening of said stationary member being somewhat greater than the diameter of the opening in the end wall of said movable member, a fixed to the end wall of said movable member and having a bearing member of air under pressure (not said bowl is prevented from leaking outwardly through the joint between the opening in the plate 21 around the shaft I9. Any leakage of air from chamber 26 into the bowl l5 will not be injurious to the material undergoing mixing within the bowl, and it is only necessary to maintain sufficient pressure of the air in chamber 254 which will overbalance the pressure within the bowl in order to thoroughly seal the joint at the trunnion of the bowl and Aprevent the liquid in, the bowl from leaking therefrom.

While in Fig. 2 the construction of the Yshaft seal at the end l2 of the machine is shown, it will be understood that a similar seal for the shaft may be constructed at the end i3. In the end I3, the agitator shaft IB carries a pulley 4S which may be connected to an electric motor or other suitable source of power not shown.

lwhereby said cylindrical lformed exteriorly on one end thereof and mounted in the opening of said stationary member member and said movable member are free to rotate with respect to said stationary member, an elongated tubular portion projecting from the end of the cylindrical member' having said bearing, said tubular portion having an external diameter corresponding substantially to the diameter of the opening in said movable member and being mounted within the opening in said movable member, the internal `opening in said tubular portion also extending through the end wall of said cylindrical member having tending through said cylindrical member,V its tubular extension and into said movable member, said shaft having a diameter less than the diameter of the opening through the tubular portion to provide'an annular chamber substantially coextensive with the portion of the cylindrical member having the tubular extension, and means mounted on each end of said tubular portion and surrounding the shaft for closing the ends of said annular chamber whereby said chamber is unobstructed throughout its length., l l 2. A device of the class described, comprising a movable member having an end wall with an opening formed thereinga stationary member arranged in spaced relation to the wall of said movable member and having an opening formed therein in alinement with the opening in the end wall of said movable member, the diameter oi' the opening of said stationary member being somewhat greater than the diameter of the opening in the end wall of'said movable member, a cylindrical member fixed to theend wall of said movable member and having a bearing portion formed exteriorly thereon, said bearing portion being mounted in the opening of s aid stationary member whereby said cylindrical member and said movable member are free to rotate with respect to said stationary member,A said cylindrical member having a main body portion extending outwardly from its bearing portion and` terminating in an outer end arranged in spaced relation with respect to the stationary member, an, elongated tubular portion projecting from the end of the cylindrical member having said exa ternal bearing, said tubular portion having .an externaldiameter corresponding substantially to the diameter of the opening in said movable member and being mounted in said opening, the internal opening in said tubular portion terminating at a distancefrom the outer end of said cylindrical member, a shaft extending through said cylindrical member, its tubular extension and into said movable member, said shaft having a diameter less than the diameter of the internalv opening of said tubular portion to provide an annular chamber substantially coextensive with a bearing mounted -vi1; the extreme outer end of said cylindrical porytllon and disposed in spaced for rotatably suppo'xting the outer end portion 5 of said shaft.

Trrus JAMES SHELLENBERGER. 

